Java program to check palindrome string using recursion

In this post let’s learn java program to check palindrome string using recursion.

Java program to check palindrome string using recursion

Recursion means a function calling itself. In this java program initially “checkPalindrome” method with String parameter “str” is created.

Also read – palindrome program in java using library methods

This method first checks if user entered string length is 0 or 1 using if statement. Here if string length is equal to 0 or 1 then string is palindrome.

If not, in the next if statement first and last character of string is checked. If first and last character of string are same then procedure is repeated for substring without first and last character.

This procedure is continued till string condition is not true. Let’s check whether string is palindrome using recursion,

import java.util.Scanner;

public class RecursivePalindromeJava 
{
public static boolean checkPalindrome(String str)
{
if(str.length() == 0 || str.length() == 1)
return true;
if(str.charAt(0) == str.charAt(str.length() - 1))
return checkPalindrome(str.substring(1, str.length() - 1));
return false;
}
   public static void main(String[]args)
{
Scanner sc = new Scanner(System.in);
System.out.println("Please enter a string : ");
String strInput = sc.nextLine();
if(checkPalindrome(strInput))
{
System.out.println(strInput + " is palindrome");
}
else
{
System.out.println(strInput + " not a palindrome");
}
sc.close();
}
}

Output:

java program to check palindrome string using recursion